BEGIN;
BEGIN
EXPLAIN (ANALYZE, BUFFERS)
select
	c_count,
	count(*) as custdist
from
	(
		select
			c_custkey,
			count(o_orderkey)
		from
			customer left outer join orders on
				c_custkey = o_custkey
				and o_comment not like '%special%packages%'
		group by
			c_custkey
	) as c_orders (c_custkey, c_count)
group by
	c_count
order by
	custdist desc,
	c_count desc;
                                                                    QUERY PLAN                                                                    
--------------------------------------------------------------------------------------------------------------------------------------------------
 Sort  (cost=847836.72..847837.22 rows=200 width=8) (actual time=36392.771..36392.774 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=220223 read=69845 written=889
   ->  HashAggregate  (cost=847827.08..847829.08 rows=200 width=8) (actual time=36392.665..36392.676 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=220220 read=69845 written=889
         ->  HashAggregate  (cost=810327.08..825327.08 rows=1500000 width=8) (actual time=35251.895..36038.414 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=220220 read=69845 written=889
               ->  Hash Right Join  (cost=69028.00..735855.01 rows=14894414 width=8) (actual time=998.513..21313.096 rows=15353296 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=220220 read=69845 written=889
                     ->  Seq Scan on orders  (cost=0.00..443410.80 rows=14894414 width=8) (actual time=0.031..9283.240 rows=14853279 loops=1)
                           Filter: ((o_comment)::text !~~ '%special%packages%'::text)
                           Rows Removed by Filter: 161721
                           Buffers: shared hit=186304 read=68483 written=889
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=986.997..986.997 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=33916 read=1362
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.015..559.504 rows=1500000 loops=1)
                                 Buffers: shared hit=33916 read=1362
 Planning time: 3.216 ms
 Execution time: 36412.727 ms
(24 rows)

COMMIT;
COMMIT